Hur was the mate of Za, leader of the Tribe of Gum, circa 100,000 BC and the daughter of Horg. She stood by her mate, even as he struggled to maintain leadership over the tribe against the outsider Kal, who sought to take advantage of Za's inability to make fire, without which the tribe could not survive.
Kal brought the First Doctor to the tribe, claiming he was able to make fire. Hur understood as well as her mate the urgency of learning this secret from the old man and his young friends before Kal could do so. When Hur suspected Old Mother planned to kill the strangers before they could make fire, she was quick to alert Za. When they learned that the old woman had instead helped the strangers escape into the forest, Hur convinced Za that they must recapture them, despite the many dangers which lurked in the night.
Hur was puzzled as to why Ian would help her and her mate, who had been injured by an animal while they pursued him. Because of the wisdom she and Za saw in these strangers, and especially because of her loyalty to her mate, Hur tried to hold back the tribe members led by Horg, who sought to kill the strangers and depose Za. She refused to listen to the strangers' pleas to be set free, even after they had saved Za by giving him the secret of fire.
Hur made the horrifying discovery of flaming skulls in the Cave, a ruse devised by Ian. Once the ruse was discovered, Hur joined her mate and the other tribe members in pursuit of the strangers, watching in amazement as the Doctor's TARDIS vanished into thin air. (TV: An Unearthly Child)